Bicycle front derailleur

ABSTRACT

A bicycle front derailleur includes a chain guide that is provided with a pushing element that is movable relative to the chain guide to assist in shifting a bicycle chain from a smaller front sprocket to an adjacent larger sprocket. The chain guide is part of a movable member that is movably coupled to a base member via a linkage assembly. The pushing element is rotatably coupled to the chain guide portion and activated by a chain to move relative to the inner chain guide member from a first position with the pushing element at rest to a second position in response to activation by the chain. The contact surface moves laterally outwardly into the chain receiving slot toward the outer chain guide member as the pushing element moves from the first position to the second position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 10/928,741 filed on Aug. 30, 2004. The entire disclosure ofU.S. patent application Ser. No. 10/928,741 is hereby incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention generally relates to a bicycle front derailleur. Morespecifically, the present invention relates to a bicycle frontderailleur that smoothly and reliably shifts a bicycle chain between thefront sprockets of the drive train, and which aggressively shifts thebicycle chain to a larger front sprocket from a smaller front sprocket.

2. Background Information

Bicycling is becoming an increasingly more popular form of recreation aswell as a means of transportation. Moreover, bicycling has become a verypopular competitive sport for both amateurs and professionals. Whetherthe bicycle is used for recreation, transportation or competition, thebicycle industry is constantly improving the various components of thebicycle. One component or part of the bicycle that has been extensivelyredesigned over the years is the front derailleur. A front derailleur istypically mounted onto the bicycle frame adjacent to the front sprocketsto shift the chain laterally between the front sprockets. Many bicycleshave two or three front sprockets.

Generally, a front derailleur includes a fixed member non-movablysecured to a bicycle frame, and a movable member supported to be movablerelative to the fixed member. Typically, the fixed member is a tubularclamping member that is secured to the seat tube. Alternatively, thefixed member is sometimes coupled to the bottom bracket or coupled to abrazed-on mounting structure of the frame. In any case, the movablemember typically has a chain guide with a pair of cage plates forcontacting and moving a chain laterally between the front sprockets. Themovable member is usually biased in a given direction relative to thefixed member by a spring. The movable member is usually moved relativeto the fixed member by pulling and/or releasing a shift control cablethat is coupled to the front derailleur. The movable member and thefixed member usually are interconnected through a plurality of pivotallinks (i.e. a linkage assembly).

One problem with typical front derailleurs is that the chain is notalways shifted from the smaller sprocket to the larger sprocket(s) asquickly (aggressively), smoothly and reliably as desired by some riders.Thus, undesirable audible clicking sounds can sometimes occur. Moreover,optimum power transfer from the rider to the bicycle might not beachieved during a front up shift (from smaller sprocket to largersprocket) of the bicycle chain.

In view of the above, it will be apparent to those skilled in the artfrom this disclosure that there exists a need for an improved bicyclefront derailleur that overcomes the above mentioned problems in theprior art. This invention addresses this need in the art as well asother needs, which will become apparent to those skilled in the art fromthis disclosure.

SUMMARY OF THE INVENTION

One object of the present invention is to provide a front bicyclederailleur that provides smooth, reliable shifting of the bicycle chainbetween the front sprockets of the drive train.

Another object of the present invention is to provide a front bicyclederailleur, which shifts the bicycle chain to a larger front sprocketfrom a smaller front sprocket more quickly (aggressively).

Another object of the present invention is to provide a bicycle frontderailleur, which facilitates efficient power transfer from the rider tothe bicycle during an up shift of the chain (from a smaller frontsprocket to a larger front sprocket).

The foregoing objects can basically be attained by providing a bicyclefront derailleur that comprises a base member, a movable member and alinkage assembly. The base member is configured to be fixedly coupled toa bicycle frame. The movable member has a chain guide portion. Thelinkage assembly is coupled between the base member and the movablemember to move the chain guide portion between a retracted position andan extended position. The chain guide portion includes an inner chainguide member, an outer chain guide member non-movably coupled to theinner chain guide member and a pushing element with a contact surface.The outer chain guide member is spaced laterally outwardly from theinner chain guide member to form a longitudinally extending chainreceiving slot between opposing inner and outer laterally facingsurfaces of the inner and outer chain guide members. The pushing elementis rotatably coupled to the chain guide portion and activated by a chainto move relative to the inner chain guide member from a first positionwith the pushing element at rest to a second position in response toactivation by the chain. The contact surface moves laterally outwardlyinto the chain receiving slot toward the outer chain guide member as thepushing element moves from the first position to the second position.

These and other objects, features, aspects and advantages of the presentinvention will become apparent to those skilled in the art from thefollowing detailed description, which, taken in conjunction with theannexed drawings, discloses preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a part of thisoriginal disclosure:

FIG. 1 is a side elevational view of a bicycle equipped with a frontderailleur in accordance with a first preferred embodiment;

FIG. 2 is an opposite side elevational view of the view of a frontshifter or shift operating device that operates the front derailleurillustrated in FIG. 1;

FIG. 3 is an enlarged outside elevational view of the front derailleurof the bicycle illustrated in FIG. 1, with the front derailleur coupledto the seat tube;

FIG. 4 is a rear perspective view of the front derailleur of the bicycleillustrated in FIGS. 1 and 3 with the chain guide in an inner most shiftposition;

FIG. 5 is a rear perspective view of the front derailleur of the bicycleillustrated in FIGS. 1 and 3 with the chain guide in themiddle/intermediate shift position;

FIG. 6 is a rear perspective view of the front derailleur of the bicycleillustrated in FIGS. 1 and 3 with the chain guide in the outer mostshift position;

FIG. 7 is an inside elevational view of the front derailleur of thebicycle illustrated in FIG. 3, with the seat tube removed for thepurpose of illustration;

FIG. 8 is a top, plan view of the front derailleur of the bicycleillustrated in FIGS. 3 and 7, with the front derailleur coupled to theseat tube;

FIG. 9 is a front elevational view of the front derailleur of thebicycle illustrated in FIGS. 3, 7 and 8, with the front derailleurcoupled to the seat tube;

FIG. 10 is a rear elevational view of the front derailleur of thebicycle illustrated in FIGS. 3 and 7-9, with the front derailleurcoupled to the seat tube;

FIG. 11 is an upper, outside perspective view the front derailleurillustrated in FIGS. 3-10 prior to shifting a chain from a smallersprocket to a larger sprocket (i.e., when the pushing element of thepushing mechanism is in an initial rest position or first position),with only two sprockets illustrated for the purpose of illustration;

FIG. 12 is an upper, outside perspective view the front derailleurillustrated in FIGS. 3-10 during an early stage of a shifting operationof a chain from a smaller sprocket to a larger sprocket (i.e., when thechain engages the pushing element of the pushing mechanism, whichlongitudinally moves the pushing element such that the pushing elementpushes the chain laterally outwardly), with only two sprocketsillustrated for the purpose of illustration;

FIG. 13 is an upper, outside perspective view the front derailleurillustrated in FIGS. 3-10 during a later stage of a shifting operationof a chain from a smaller sprocket to a larger sprocket (i.e., when thechain still engages the pushing element of the pushing mechanism, whichlongitudinally moves the pushing element such that the pushing elementpushes the chain laterally outwardly), with only two sprocketsillustrated for the purpose of illustration;

FIG. 14 is an upper, outside perspective view the front derailleurillustrated in FIGS. 3-10 during final stage of a shifting operation ofa chain from a smaller sprocket to a larger sprocket (i.e., when thepushing element of the pushing mechanism is in a final moved position orsecond position after pushing the chain laterally onto the largersprocket), with only two sprockets illustrated for the purpose ofillustration;

FIG. 15 is a further enlarged, top plan view of the inner guide memberof the front derailleur illustrated in FIGS. 3 and 7-10, with portionsbroken away for the purpose of illustration of the pushing mechanism(with the pushing element of the pushing mechanism located in an initialrest or first position);

FIG. 16 is a further enlarged, top plan view of the inner guide memberof the front derailleur illustrated in FIGS. 3 and 7-10, with portionsbroken away for the purpose of illustration of the pushing mechanism(with the pushing element of the pushing mechanism located in a finalmoved or second position);

FIG. 17 is a further enlarged, top plan view of the inner guide memberof the front derailleur illustrated in FIGS. 3 and 7-10, with portionsbroken away for the purpose of illustration of the pushing mechanism andwith portions of the pushing mechanism removed for the purpose ofillustration;

FIG. 18 is an enlarged, partial cross-sectional view of the pushingmechanism illustrated in FIGS. 15 and 16, as seen along section line18-18 of FIG. 15;

FIG. 19 is an enlarged, partial front side perspective view of thepushing mechanism of the front derailleur illustrated in FIGS. 3-14;

FIG. 20 is an enlarged, partial rear side perspective view of thepushing mechanism of the front derailleur illustrated in FIGS. 3-14;

FIG. 21 is a side elevational view of a bicycle equipped with a frontderailleur in accordance with a second preferred embodiment of thepresent invention;

FIG. 22 is an enlarged outside elevational view of the front derailleurof the bicycle illustrated in FIG. 21 in accordance with the secondpreferred embodiment of the present invention, with the front derailleurcoupled to the seat tube;

FIG. 23 is a rear perspective view of the front derailleur illustratedin FIG. 22 with the chain guide in an inner most shift position;

FIG. 24 is a rear perspective view of the front derailleur illustratedin FIG. 22 with the chain guide in the middle/intermediate shiftposition;

FIG. 25 is a rear perspective view of the front derailleur illustratedin FIG. 22 with the chain guide in the outer most shift position;

FIG. 26 is an inside elevational view of the front derailleurillustrated in FIG. 22, with the seat tube removed for the purpose ofillustration;

FIG. 27 is a top, plan view of the front derailleur illustrated in FIGS.22 and 26, with the front derailleur coupled to the seat tube;

FIG. 28 is a front elevational view of the front derailleur illustratedin FIGS. 22, 26 and 27, with the front derailleur coupled to the seattube;

FIG. 29 is a rear elevational view of the front derailleur illustratedin FIGS. 22 and 26-28, with the front derailleur coupled to the seattube;

FIG. 30 is an upper, outside perspective view the inner guide member ofthe front derailleur illustrated in FIGS. 22-29 during a shiftingoperation of a chain from a smaller sprocket (not shown) to a largersprocket (not shown);

FIG. 31 is a partial, top plan view of the front derailleur illustratedin FIGS. 22-29 during a shifting operation of a chain from a smallersprocket (not shown) to a larger sprocket (not shown);

FIG. 32 is a further enlarged, top plan view of the inner guide memberof the front derailleur illustrated in FIGS. 22 and 26-29, with portionsbroken away for the purpose of illustration of the pushing mechanism(with the pushing element of the pushing mechanism located in an initialrest or first position); and

FIG. 33 is a further enlarged, top plan view of the inner guide memberof the front derailleur illustrated in FIGS. 22 and 26-29, with portionsbroken away for the purpose of illustration of the pushing mechanism(with the pushing element of the pushing mechanism located in a finalmoved or second position).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Selected embodiments of the present invention will now be explained withreference to the drawings. It will be apparent to those skilled in theart from this disclosure that the following descriptions of theembodiments of the present invention are provided for illustration onlyand not for the purpose of limiting the invention as defined by theappended claims and their equivalents.

Referring initially to FIGS. 1-3, a bicycle 10 with a front derailleur12 is illustrated in accordance with a first embodiment. The frontderailleur 12 is relatively conventional, except the front derailleur 12includes a chain guide portion 26 with a chain pushing mechanism 28 inaccordance with the present invention. Specifically, the pushingmechanism 28 is arranged and configured to move relative to the chainguide portion 26 in order to assist in up shifting in accordance withthe present invention. The pushing mechanism 28 is preferably a chainactivated mechanism that moves relative to the chain guide portion 26,independently of movement of other parts of the front derailleur 12. Thepushing mechanism 28 is preferably movably attached to the chain guideportion 26 without being attached to other parts of the front derailleur12. The pushing mechanism 28 and the chain guide portion 26 will beexplained below in more detail.

The front derailleur 12 is fixedly coupled to a seat tube 14 of abicycle frame 13. The front derailleur 12 is operated in a relativelyconventional manner by a shifting unit 16 via a shift control cable 18to move a chain 20 by the chain guide portion 26 between three frontsprockets 22 a, 22 b and 22 c of the drive train. The shifting unit 16is mounted on the handlebar 24 as seen in FIG. 2. The shifting unit 16is conventional. While the front derailleur 12 is illustrated as athree-stage or three position derailleur that shifts the chain 20between the three front sprockets 22 a, 22 b and 22 c of the drivetrain, it will be apparent to those skilled in the art from thisdisclosure that the front derailleur 12 can be used in a drive trainwith only two front sprockets as needed and/or desired.

Bicycles and their various components are well known in the art, andthus, bicycle 10 and its various components will not be discussed and/orillustrated in detail herein, except for the components that relate tothe present invention. In other words, only the front derailleur 12 andthe components that relate thereto will be discussed and/or illustratedin detail herein. As used herein, the following directional terms“forward, rearward, above, downward, vertical, horizontal, below andtransverse” as well as any other similar directional terms refer tothose directions of a bicycle equipped with the present invention.Accordingly, these terms, as utilized to describe the present inventionshould be interpreted relative to a bicycle equipped with the presentinvention.

Referring now to FIGS. 3-10, the front derailleur 12 of the presentinvention will now be discussed in more detail. The front derailleur 12basically includes a base member 30, an inner link member 32, an outerlink member 34, a movable member 36 and a biasing member 38. The movablemember 36 has the chain guide portion 26 with the pushing mechanism 28movably coupled thereto in accordance with the present invention. Thebase member 30 is fixedly coupled to the seat tube 14 of the bicycleframe 13. The inner and outer link members 32 and 34 are pivotallycoupled to both the base member 30 and the movable member 36 to form afour bar linkage such that the chain guide portion 26 is movable betweena retracted position and an extended position, as best seen in FIGS.4-6. More specifically, the chain guide portion 26 is movable between aninnermost retracted position, an intermediate retracted/extendedposition and an outermost extended position as best seen in FIGS. 4-6,respectively.

Specifically, the inner and outer link members 32 and 34 are pivotallycoupled to the base member 30 at their upper ends to pivot relative tothe base member 30 about upper (inner and outer) pivot axes A and B,respectively. The inner and outer link members 32 and 34 are alsopivotally coupled to the movable member 36 at their lower ends to pivotrelative to the movable member 36 about lower (inner and outer) pivotaxes C and D, respectively. The biasing member 38 is preferably disposedon the pivot axis C, and is preferably located on a front side of theinner link member 32. More specifically, the biasing member 38 isoperatively coupled between the inner link member 32 and the movablemember 36 to apply an urging force that normally biases the movablemember 36 toward the seat tube 14 of the bicycle frame 13 (i.e. toward acenter plane P of the bicycle 10).

In the illustrated embodiment, the front derailleur 12 is a bottom swingtype front derailleur. Thus, the movable member 36 moves laterallyoutward and upwardly relative to the center longitudinal plane P of thebicycle frame 13 when the control cable 18 is pulled by the shiftingunit 16. Accordingly, the movable member 36 moves laterally towards/awayfrom the seat tube 14 of the bicycle frame 13 to shift the chain 20laterally between the front sprockets 22 a, 22 b and 22 c by operatingthe shifting unit 16, which releases/pulls the shift control cable 18.In other words, the inner and outer links 32 and 34 swing below thepivot axes A and B to form a four bar linkage assembly together with thebase member 30 and the movable member 36 of the front derailleur 12 in arelatively conventional manner.

The base member 30 basically includes a frame fixing portion 40 and aderailleur support portion 42 fixedly attached to the frame fixingportion 40. The frame fixing portion 40 and the derailleur supportportion are fixed coupled together by main fixing bolt 44. Specifically,a curved surface of the derailleur support portion 42 is received in amating recess of the frame fixing portion 40 to prevent relativerotation of the derailleur support portion 42 relative to the framefixing portion 40. Then, the main fixing bolt 44 is inserted through ahole (not shown) of the frame fixing portion 40 into a threaded blindbore (not shown) of the derailleur support portion 42 in a conventionalmanner. The derailleur support portion 42 pivotally supports the innerand outer link members 32 and 34. Preferably, the parts of the basemember 30 are constructed of lightweight rigid materials such asmetallic materials. However, some of the parts can be constructed ofother materials such as hard, rigid non-metallic materials (e.g., suchas a hard plastic material).

The frame fixing portion 40 basically includes a first C-shaped tubularclamping member 40 a, a second C-shaped tubular clamping member 40 b, apivot pin 40 c and a threaded fastener 40 d. Thus, the frame fixingportion 40 is preferably a tubular clamping portion of the base member30. The pivot pin 40 c pivotally couples a pair of adjacent ends of thetubular clamping members 40 a and 40 b together in a conventionalmanner. The fastener 40 d releaseably couples the free ends of thetubular clamping members 40 a and 40 b together in a conventionalmanner. For example, the fastener 40 d is preferably a screw or boltthat extends through a hole in the free end of the second clampingmember 40 b and that is threaded into a nut, or the like in aconventional manner. Alternatively, the fastener 40 d can be directlythreaded into a threaded hole of the first clamping member 40 a. Acenter frame mounting axis X is formed by the curved inner mountingsurfaces of the first and second clamping members 40 a and 40 b, whichsubstantially corresponds to the center axis of the seat tube 14 andlies in the center plane P when coupled to the frame 13.

The first tubular clamping member 40 a preferably has the derailleursupport portion 42 fixedly attached thereto. Thus, the base member 30 isbasically constructed of three pieces (i.e., the clamping members 40 aand 40 b, and the derailleur support portion 42) that are all preferablyconstructed of a lightweight, rigid material. Preferably, these partsare constructed of metal utilizing conventional manufacturing techniquessuch as casting and/or machining. However, it will be apparent to thoseskilled in the art from this disclosure that the clamping members 40 aand 40 b could be constructed of other materials and/or could beconstructed using other manufacturing techniques as needed and/ordesired. Moreover, it will be apparent to those skilled in the art fromthis disclosure that the derailleur support portion 42 could beintegrally formed with the first clamping member 40 a as needed and/ordesired.

The derailleur support portion 42 of the base member 30 has the innerand outer link members 32 and 34 pivotally coupled thereto, as mentionedabove. Specifically, the derailleur support portion 42 includes a pairof inner mounting flanges or attachment elements 46 a and 46 b and anouter mounting flange or attachment element 48. The inner link member 32is pivotally coupled between the attachment elements 46 a and 46 b,while the outer link member 34 is pivotally coupled to the outerattachment element 48.

A pair of threaded adjustment holes (not shown) have vertical adjustmentscrews threadedly coupled therein to control the movement of the innerlink member 32, and thus, the movable member 36. The adjustment screwscan be rotated to adjust their vertical positions such that their freeends selectively contact the inner link member 32 to control the rangeof movement of the inner link member 32, and thus, control the range ofmovement of the movable member 36, in a relatively conventional manner.

The attachment elements 46 a and 46 b of the derailleur support portion42 extend downwardly and are substantially parallel to each other. Theattachment element 46 b is spaced longitudinally rearwardly from theattachment element 46 a. Accordingly, a recess is formed between theattachment elements 46 a and 46 b for pivotally receiving the inner linkmember 32 therebetween. The outer (upper) attachment element 48 of thederailleur support portion 42 pivotally supports the outer link member34. Pivot pins or the like are used to couple the inner and outer linkmembers 32 and 34 to the inner attachment elements 46 a and 46 b and tothe outer attachment element 48 in a conventional manner.

Referring still to FIGS. 3-10, the inner link member 32 basicallyincludes an upper coupling portion 50, a lower coupling portion 52 and atransitional portion 54 arranged between the upper and lower couplingportions 50 and 52. The inner link member 32 is preferably constructedof a lightweight, rigid material. Specifically, the inner link member 32is preferably constructed of metal as a one-piece, unitary memberutilizing conventional manufacturing techniques such as casting and/ormachining. However, it will be apparent to those skilled in the art fromthis disclosure that the inner link member 32 could be constructed ofother materials and/or could be constructed using other manufacturingtechniques as needed and/or desired.

The upper coupling portion 50 of the inner link member 32 is pivotallycoupled to the base member 30 between the inner attachment elements 46 aand 46 b, while the lower coupling portion 52 of the inner link member32 is pivotally coupled to the movable member 36. The upper couplingportion 50 is preferably wider (thicker) than the lower coupling portion52, as measured in the longitudinal direction of the bicycle 10.Moreover, the lower coupling portion 52 is preferably offset in therearward direction of the bicycle 10 from the upper coupling portion 50.The transitional portion 54 has a varying thickness that decreases asthe transitional portion 54 approaches the lower coupling portion 52from the upper coupling portion 50.

The upper coupling portion 50 preferably includes a pair of projections(not shown in detail) designed to selectively contact the lower ends ofthe adjustment screws mounted to the derailleur support portion 42, in aconventional manner. The lower coupling portion 52 preferably includesan abutment projection 56 that is configured to optionally engage oneend of a biasing member. However, in the illustrated embodiment, the endof the biasing member 38 extends upwardly to engage the transitionportion 54 rather than the projection 56. In other words, depending onthe type of biasing member desired, the projection 56 may or may not beutilized.

Referring still to FIGS. 3-10, the outer link member 34 basicallyincludes an upper coupling portion 60, a lower coupling portion 62 and acable attachment portion 64 extending from the upper coupling portion60. The outer link member 34 is preferably constructed of a lightweight,rigid material. Specifically, the outer link member 34 is preferablyconstructed of metal as a one-piece, unitary member utilizingconventional manufacturing techniques such as casting and/or machining.However, it will be apparent to those skilled in the art from thisdisclosure that the outer link member 34 could be constructed of othermaterials and/or could be constructed using other manufacturingtechniques as needed and/or desired.

The upper coupling portion 60 of the outer link member 34 is pivotallycoupled to the outer (upper) attachment element 48 of the base member30, while the lower coupling portion 62 of the outer link member 34 ispivotally coupled to the movable member 36. The upper coupling portion60 is preferably wider (thicker) than the lower coupling portion 62, asmeasured in the longitudinal direction of the bicycle 10. The cableattachment portion 64 of the outer link member 34 extends upwardly fromthe upper coupling portion 60, and is configured to have the controlcable 18 fixedly coupled thereto via a cable attachment device in aconventional manner. Thus, when the control cable 18 is pulled/released,the outer link member 34 will rotate about the pivot axis B to move themovable member 36 laterally relative to the base member 30.

The upper coupling portion 60 of the outer link member 34 includes apair of longitudinally spaced parallel (front and rear) mounting flangesor attachment elements 66 a and 66 b that are configured to receive theouter attachment element 48 of the base member 30 longitudinallytherebetween. The lower coupling portion 62 of the outer link member 34is pivotally coupled to the movable member 36. The cable attachmentportion 64 is narrower (thinner) than both the upper coupling portion 60and the lower coupling portion 62 in the longitudinal direction of thebicycle 10. The cable attachment portion 64 extends from the rearwardside of the upper coupling portion 60. The cable attachment portion 64basically includes a threaded through bore 68 configured to have thecable fixing device mounted thereto in a conventional manner, asmentioned above.

Referring now to FIGS. 3-18, the movable member 36 in accordance withthe present invention will now be discussed in more detail. The movablemember 36 basically includes an inner chain guide member 70, an outerchain guide member 72 and the pushing mechanism 28. Preferably, theinner and outer chain guide members 70 and 72 are each constructed of alightweight rigid material such as a metallic material in a conventionalmanner (e.g., by machining, casting and/or by bending a rigid sheetmaterial) to form the desired shape. The inner and outer guide members70 and 72 are fixedly, non-movably coupled together to form a chainreceiving slot therebetween, while the pushing mechanism 28 ispreferably movable attached to the inner chain guide member 70.

In this embodiment, the pushing mechanism 28 is slidably attached to theinner guide member 70 of the movable member 36 to move relative thereto.Specifically, the pushing mechanism 28 is preferably slidably coupled tothe inner guide member 70 via a protrusion and recess arrangement, asexplained below in more detail. However, it will be apparent to thoseskilled in the art from this disclosure that the pushing mechanism 28could be coupled to other parts of the movable member 36 (i.e., insteadof or in addition to the inner guide member 70) if needed and/ordesired. Moreover, it will be apparent to those skilled in the art fromthis disclosure that the movable member 36 could include a modifiedpushing mechanism that moves in a different manner than the pushingmechanism 28. For example, the movable member 36 could include arotatable, cam-shaped pushing element instead of slidable pushingmechanism 28, as discussed below with reference to another preferredembodiment of the present invention.

Referring mainly to FIGS. 11-20, the inner guide member 70 basicallyincludes an inner chain guide plate element 74, a pair of inner mountingflanges 76 a and 76 b, a pair of outer mounting flanges 78 a and 78 band a mounting recess 80. The inner and outer mounting flanges 76 a, 76b, 78 a and 78 b extend upwardly from the inner guide plate element 74to form a mounting portion of the movable member 36. The chain guideplate element 74 has the mounting recess 80 formed therein for movablyreceiving the pushing mechanism 28 therein, as explained in more detailbelow.

The inner mounting flanges 76 a and 76 b have the lower coupling portion52 of the inner link member 32 pivotally coupled therebetween forrotation about the pivot axis C, while the outer mounting flanges 78 aand 78 b have the lower coupling portion 62 of the outer link member 34pivotally coupled therebetween for rotation about the pivot axis D.Pivot pins or the like are used to couple the inner and outer linkmembers 32 and 34 to the mounting flanges 76 a and 76 b, and to themounting flanges 78 a and 78 b, respectively, in a conventional manner.The inner guide member 70 is preferably constructed by casting and/ormachining a single piece of metallic material.

The inner chain guide plate element 74 further includes a rearattachment opening 82 a, a front attachment opening 82 b and a pair ofside attachment openings 82 c and 82 d. The rear attachment opening 82 ais preferably a threaded opening configured to receive a pair of firstfasteners 84 from opposite lateral sides thereof. Specifically, one ofthe fasteners 84 is preferably used to fixedly attach the outer guidemember 72 to the inner guide member 70, while the other fastener 84 isused to attach part of the pushing mechanism 28 to the inner guidemember 70, as explained below. In the illustrated embodiment, thefasteners 84 are screws and the rear attachment opening 82 a has a pairof oppositely threaded sections configured to threaded receive thefasteners 84 therein. The front attachment opening 82 b is preferably avertical opening that receives a rivet or the like in order to fixedlycouple the outer guide member 72 to the inner guide member 70. The sideattachment openings 82 c and 82 d are used to couple another part of thepushing mechanism 28 to the inner guide member 70, as also explainedbelow.

The mounting recess 80 includes front and rear stops 80 a and 80 b aswell as a mounting surface 80 c to control movement of the pushingmechanism 28. Preferably, the front and rear stops 80 a and 80 b arecoated with resilient material such as rubber. The mounting surface 80 cextends in a substantially longitudinal direction in an area between thefront and rear stops 80 a and 80 b. More specifically, the mountingsurface 80 c is preferably a substantially vertical surface that formsan angle θ relative to the center plane P of between about 5° and about10°. Preferably, the angle θ is about 5°. The pushing mechanism 28 ispreferably attached to the mounting surface 80 c using the sideattachment openings 82 c and 82 d. In particular, the side attachmentopenings 82 c and 82 d extend between the mounting surface 80 c and thelaterally inside surface of the inner chain guide plate element 74 suchthat a pair of secondary fasteners or screws 86 can be inserted thereinand threadedly coupled to part of the pushing mechanism 28.

In the illustrated embodiment, the pushing mechanism 28 basicallyincludes a fixed track 90, a movable chain pushing element 92 and abiasing element 94. The track 90 is fixed attached to the inner guideelement 74 within the mounting recess 80 with the pair of fasteners orscrews 86. The pushing element 92 is freely slidably mounted to thetrack 90 to move between the front and rear stops 80 a and 80 b. Inparticular, part of the pushing element 92 is received in the track 90to form a protrusion and recess arrangement together with the track 90.The biasing element 94 is preferably coupled between the pushing element92 and one of the fasteners 84 at the rear of the movable member 36 tourge the pushing element 92 substantially in the rearward direction.

More specifically, the pushing element 92 slides relative to the track90, and thus, relative to the inner chain guide plate element 74. Due tothe inclination of the mounting surface 80 c, the pushing element 92preferably slides in a substantially longitudinal direction (i.e., at anangle of about 5° relative to the center plane P). More specifically,the pushing element slides from an initial (first) position where itsouter most edge is spaced a distance d₁ of about 1.0 millimeter from theside surface of the inner chain guide plate element 74 as seen in FIG.15 to a final moved (second) position in which its outer most edge isspaced a distance d₂ of about 4.0 millimeters from the side surface ofthe inner chain guide plate element 74 as seen in FIG. 16. Thus, due tothe inclination of the of the mounting surface 80 c, the pushing element92 moves both longitudinally forward and laterally outward as it movesfrom the first position to the second position as seen in FIGS. 15 and16.

The pushing element 92 is chain activated. In other words, the pushingelement 92 normally moves with the movable member 36 and does not moverelative to the movable member 36, unless the chain 20 contacts thepushing element 92 during an up shift. When the moving chain 20 contactsthe pushing element 92 during an up shift, the pushing element 92 thenmoves relative to the movable member 36 to push the chain laterallyoutwardly as the pushing element 92 slides forward.

The fixed track 90 basically includes a mounting plate 90 a and a pairof support plates 90 b and 90 c that extend outwardly from the mountingplate to form a substantially U-shaped cross-sectional shape. Eachsupport plate 90 b and 90 c has a longitudinal groove formed therein, asseen in FIGS. 15-18. The front and rear ends of the track 90 preferablyhave U-shaped retainer members 91 a and 91 b mounted therein,respectively. The retainer members 91 a and 91 b are preferablyconstructed of plastic, and are arranged and configured to limitmovement of top and bottom bearing structures 93 that are mountedbetween the pushing element 92 and the support plates 90 b and 90 c.Specifically, each bearing structure 93 preferably includes a pluralityof longitudinally arranged ball bearings (only two shown) that areretained in a plastic holder, as best seen in FIG. 18. The ball bearingsare partially received in longitudinal grooves of both the pushingelement 92 and the support plates 90 b and 90 c, as best seen in FIGS.15-18.

The pushing element 92 basically includes a sliding part 96 and a chaincontact part 98 that are fixedly attached to each other by a pair ofscrews 100. The sliding part 96 has longitudinal grooves formed thereinthat are opposed to the longitudinal grooves of the support plates 90 band 90 c for receiving the bearing structures therebetween. Preferablythe front and rear ends of the sliding part 96 have plastic pads coupledthereto, which selectively contact the front and rear stops 80 a and 80b when the pushing element 92 moves to the end positions. The slidingpart 96 is partially received within the track 90 to form a protrusionand recess arrangement.

The chain contact part 98 includes a contoured chain contact surface 102that includes a plurality of segmented sections. The chain contactsurface 102 includes a main section S that is substantially parallel tothe center plane P, while a plurality of other sections slope toward thecenter plane P from the main section S. Thus, the main section S is thelaterally outermost section of the segmented contact surface 102. In anycase, the chain contact surface 102 moves laterally outwardly andlongitudinally forwardly as the pushing element 92 moves from the firstposition to the second position. The biasing member 94 (spring) iscoupled within a hole in the rear end of the chain contact part 98. Thebiasing member 94 is also coupled to a hook 104, which is fixed to theinner chain guide plate element 74 via one of the fasteners (screws) 84,as seen in FIG. 7.

The outer guide member 72 is fixedly coupled to the inner guide member70. Specifically, the rear of the chain guide member 72 is coupled tothe rear of the inner chain guide plate element 74. The outer guidemember 72 basically includes a rear mounting portion 72 a, a frontmounting portion 72 b and an outer chain guide plate element 72 c thatis laterally spaced from the inner chain guide plate element 74. Theouter chain guide plate element 72 c and the inner chain guide plateelement 74 with the pushing mechanism 28 form the chain guide portion 26of the present invention with a chain receiving slot.

The biasing member 38 will now be discussed in more detail. The biasingmember 38 is preferably a coil spring that is axially mounted on thepivot pin at the pivot axis C in front of the second coupling portion 52of the inner link member 32, but rearwardly of the front attachmentelement 76 a of the movable member 36. Thus, the biasing member 38preferably includes a front end 110, a rear end 112 and a coiled portion114 extending between the front and rear ends 110 and 112. The rear end112 preferably extends radially outwardly from the coiled portion 114and engages the transition portion 54 of the inner link member 32. Onthe other hand, the front end 110 preferably extends tangentiallyoutwardly from the coiled portion 114 and engages the inner shift plate74 of the movable member 36. The front end 110 is also supported by therearward facing surface of the front attachment element 76 a of themovable member 36. Thus, the front end 110 of the biasing member 38 islocated in front of the upper coupling portion 50 of the inner linkmember 32.

Second Embodiment

Referring now to FIGS. 21-33, a bicycle 10′ with a modified frontderailleur 12′ in accordance with a second embodiment will now beexplained. The bicycle 10′ is identical to the bicycle 10 of the firstembodiment, except for the modified front derailleur 12′. Moreover, thefront derailleur 12′ is identical to the front derailleur 12 of thefirst embodiment, except the front derailleur 12′ includes a modifiedinner link member 32′, a modified movable member 36′ with a modifiedpushing element 28′ coupled thereto, and a modified biasing member 38′.

In view of the similarity between the first and second embodiments, theparts of the second embodiment that are identical to the parts of thefirst embodiment will be given the same reference numerals as the partsof the first embodiment. Moreover, in view of the similarity between thefirst and second embodiments, parts of this second embodiment that arefunctionally identical to parts of the first embodiment will be giventhe same reference numerals as the first embodiment but with a prime“′”. Accordingly, the descriptions of the parts of the second embodimentthat are identical to the parts of the first embodiment may be omittedfor the sake of brevity, and the descriptions of the parts of the secondembodiment that are functionally identical to the parts of the firstembodiment may be reduced for the sake of brevity. However, it will beapparent to those skilled in the art from this disclosure that thedescriptions and illustrations of the first embodiment also apply tothis second embodiment, except as explained and illustrated herein.

The modified front derailleur 12′ basically includes a base member 30,the inner link member 32′, an outer link member 34, the movable member36′ with the pushing mechanism 28′ and the biasing member 38′. The innerlink member 32′ is identical to the inner link member 32, except theinner link member 32′ has a transition portion 54′ that extends furtherrearwardly from an upper coupling portion 50′ such that a lower couplingportion 52′ is spaced further rearwardly than in the first embodiment.The lower coupling portion 52′ preferably includes an abutmentprojection 56′ that engages the modified biasing member 38′ in thisembodiment.

The biasing member 38′ is identical to the biasing member 38 of thefirst embodiment, except the biasing member 38′ includes modified frontand rear ends 110′ and 112′. The front end 110′ extends tangentiallyfrom the lateral inside of a coiled portion 114′ of the biasing member38′ rather than the lateral outside as in the first embodiment. Thesecond end 112′ extends radially downwardly from the coiled portion 114′rather than radially upwardly as in the first embodiment. The second end112′ engages the abutment projection 56′ rather than the transitionportion as in the first embodiment. The first end 110′ engages the chainguide portion 26′ in a manner similar to the first embodiment, except asexplained and illustrated herein.

The modified movable member 36′ basically includes an inner chain guidemember 70′, an outer chain guide member 72′ and the pushing mechanism28′. The inner and outer guide members 70′ and 72′ are fixedly,non-movably coupled together to form a chain receiving slottherebetween, while the pushing mechanism 28′ is preferably movableattached to the inner chain guide member 70′.

In this embodiment, the pushing mechanism 28′ is rotatably attached tothe inner guide member 70′ of the movable member 36′ to move relativethereto. The inner guide member 70′ basically includes an inner chainguide plate element 74′, a pair of inner mounting flanges 76 a′ and 76b′, a pair of outer mounting flanges 78 a′ and 78 b′ and a mountingrecess 80′ and a mounting plate 81′ spaced upwardly from the mountingrecess 80′ to support the pushing mechanism 28′. The mounting recess 80′is simply a cutout formed in the inner chain guide plate element 74′ formovably receiving the pushing mechanism 28′ therein. The inner and outerguide members 70′ and 72′ are each preferably constructed by castingand/or machining a single piece of metallic material.

The inner chain guide plate element 74′ further includes a rearattachment opening 82 a′, a pair of front attachment openings (notshown) and a pair of vertical attachment openings 82 c′ and 82 d′. Therear attachment opening 82 a′ is preferably a horizontal threadedopening (i.e., threaded in a single direction) configured to receive amodified fastener 85′. Specifically, the fastener 85′ is preferably anelongated screw/bolt with a roller/spacer mounted thereon to space theinner and outer guide members 70′ and 72′, which is used to fixedlyattach the outer guide member 72′ to the inner guide member 70′. Thefront attachment openings (not shown) are preferably horizontal threadedopenings that receive threaded front fasteners 83′ in order to fixedlycouple the outer guide member 72′ to the inner guide member 70′. Theattachment openings 82 c′ and 82 d′ are formed in the mounting plate 81′and the inner chain guide plate element 74′, respectively. Theattachment openings 82 c′ and 82 d′ are used to couple part of thepushing mechanism 28′ to the inner guide member 70′, as also explainedbelow.

In the illustrated embodiment, the pushing mechanism 28′ basicallyincludes a pivot pin 90′, a movable chain pushing element 92′ and abiasing element 94′. The pivot pin 90′ is preferably fixed attached tothe inner guide element 74′ within the attachment openings 82 c′ and 82d′ via a press fit or the like. The pushing element 92′ is freelyrotatably mounted on the pivot pin 90′ to rotate about a rotation axisR. The biasing element 94′ is preferably coupled between the pushingelement 92′ and the inner chain guide plate element 74′.

More specifically, the pushing element 92′ rotates relative to the pivotpin 90′, and thus, relative to the inner chain guide plate element 74′.Due to the arrangement of the biasing element 94′ and the pushingelement 92′, the pushing element 92′ rotates from an initial (first)position where its outer most edge is spaced a distance d₁′ of about 1.0millimeter from the side surface of the inner chain guide plate element74′ as seen in FIG. 32 to a final moved (second) position in which itsouter most edge is spaced a distance d₂′ of about 3.0 millimeters fromthe side surface of the inner chain guide plate element 74′ as seen inFIG. 33 during an up shift from a smaller sprocket to a larger sprocket.Then the pushing element 92′ rotates in the same rotational directionback to the first position shown in FIG. 32 after the up shift. Thebiasing element 94′ applies rotational resistance when the pushingelement 92′ is being rotated through the second position (FIG. 33) backto the first position (FIG. 32) such that the pushing element 92′ isautomatically returned to the first position after an up shift.

The pushing element 92′ is chain activated. In other words, the pushingelement 92′ normally moves with the movable member 36′ and does not moverelative to the movable member 36′, unless the chain 20 contacts thepushing element 92′ during an up shift. When the moving chain 20contacts the pushing element 92′ during an up shift, the pushing element92′ then moves relative to the movable member 36′ to push the chainlaterally outwardly as the pushing element 92′ rotates in thecounter-clockwise direction as seen in FIGS. 32 and 33.

The pushing element 92′ basically includes a movement control part 96′and a chain contact part 98′ that are fixedly attached to each other.The movement control part 96′ has a cam shaped outer control surfacethat engages the biasing element 94′. Preferably, the movement controlpart 96′ and the chain contact part 98′ are integrally formed togetheras a one-piece, unitary member of a lightweight, rigid material such asaluminum using conventional manufacturing techniques.

The chain contact part 98′ includes a cam-shaped chain contact surface102′. The chain contact surface 102′ moves laterally outwardly andlongitudinally forwardly as the pushing element 92′ moves from the firstposition to the second position. More specifically, the part of thechain contact surface 102′ that projects laterally out of the recess 80′moves longitudinally forwardly along a chain moving direction CM as itis rotated by the chain 20. Due to the cam shape of the pushing element92′, the chain contact surface 102′ moves laterally outwardly as thepushing element 92′ moves from the first position to the second position(i.e., in the area that contacts the chain 20. The biasing member 94′(spring) is coupled on a bolt 104′ that is fixed in a hole of themounting plate 81′. The one end of the biasing member 94′ engages theinner chain guide plate element 74′ while the other end engages the camshaped outer surface of the control part 96′.

The outer guide member 72′ is fixedly coupled to the inner guide member70′. Specifically, the rear of the outer chain guide member 72′ iscoupled to the rear of the inner chain guide plate element 74′. Theouter guide member 72′ basically includes a rear mounting portion 72 a′,a front mounting portion 72 b′ and an outer chain guide plate element 72c′ that is laterally spaced from the inner chain guide plate element74′. The outer chain guide plate element 72 c′ and the inner chain guideplate element 74′ with the pushing mechanism 28′ form the chain guideportion 26′ of the present invention with a chain receiving slot.

The terms of degree such as “substantially”, “about” and “approximately”as used herein mean a reasonable amount of deviation of the modifiedterm such that the end result is not significantly changed.

While only selected embodiments have been chosen to illustrate thepresent invention, it will be apparent to those skilled in the art fromthis disclosure that various changes and modifications can be madeherein without departing from the scope of the invention as defined inthe appended claims. Furthermore, the foregoing descriptions of theembodiments according to the present invention are provided forillustration only, and not for the purpose of limiting the invention asdefined by the appended claims and their equivalents.

1. A bicycle front derailleur comprising: a base member configured to befixedly coupled to a bicycle frame; a movable member having a chainguide portion; and a linkage assembly coupled between the base memberand the movable member to move the chain guide portion between aretracted position and an extended position, the chain guide portionincluding an inner chain guide member, an outer chain guide membernon-movably coupled to the inner chain guide member and a pushingelement with a contact surface, the outer chain guide member beingspaced laterally outwardly from the inner chain guide member to form alongitudinally extending chain receiving slot between opposing inner andouter laterally facing surfaces of the inner and outer chain guidemembers, the pushing element being rotatably coupled to the chain guideportion and contacted and activated by a chain to move relative to theinner chain guide member from a first position with the pushing elementat rest to a second position in response to activation by the chain, thecontact surface moving laterally outwardly into the chain receiving slottoward the outer chain guide member as the pushing element moves fromthe first position to the second position.
 2. The bicycle frontderailleur according to claim 1, wherein the pushing element is normallybiased toward the first position from the second position by a biasingelement such that the contact surface is located laterally further fromthe outer chain guide member in the first position with the pushingelement at rest than in the second position.
 3. The bicycle frontderailleur according to claim 2, wherein the pushing element isrotatably attached to inner chain guide member for rotation about arotation axis.
 4. The bicycle front derailleur according to claim 3,wherein the rotation axis extends in a substantially vertical directionrelative to the bicycle frame.
 5. The bicycle front derailleur accordingto claim 1, wherein the pushing element is coupled in a non-cableoperated arrangement.
 6. The bicycle front derailleur according to claim1, wherein the pushing element is not attached to the base member and isnot attached to the linkage assembly such that the pushing element movesindependently of movement of the linkage assembly.
 7. The bicycle frontderailleur according to claim 1, wherein the pushing element isrotatably to the chain guide portion for rotation about a rotation axisthat extends in a substantially vertical direction relative to thebicycle frame.
 8. The bicycle front derailleur according to claim 1,wherein the contact surface is a cam-shaped surface configured to movelaterally outwardly as the pushing element rotates to the secondposition from the first position.
 9. The bicycle front derailleuraccording to claim 8, wherein a portion of the contact surfaceprojecting into the chain receiving slot moves in a longitudinallyforward direction in an area adjacent the inner chain guide member asthe pushing element rotates to the second position from the firstposition.
 10. The bicycle front derailleur according to claim 8, whereinthe pushing element is normally biased toward the first position fromthe second position by a biasing element.
 11. The bicycle frontderailleur according to claim 10, wherein the pushing element includes acam-shaped control surface that engages the biasing element such thatthe pushing element is normally biased toward the first position fromthe second position by the biasing element.
 12. The bicycle frontderailleur according to claim 11, wherein the pushing element rotatesfrom the first position to the second position and back to the firstposition in a single rotational direction.
 13. The bicycle frontderailleur according to claim 8, wherein the pushing element rotatesfrom the first position to the second position and back to the firstposition in a single rotational direction.
 14. The bicycle frontderailleur according to claim 1, wherein the pushing element rotatesfrom the first position to the second position and back to the firstposition in a single rotational direction.
 15. The bicycle frontderailleur according to claim 2, wherein the pushing element includes acam-shaped control surface that engages the biasing element such thatthe pushing element is normally biased toward the first position fromthe second position by the biasing element.
 16. The bicycle frontderailleur according to claim 15, wherein the pushing element rotatesfrom the first position to the second position and back to the firstposition in a single rotational direction.
 17. The bicycle frontderailleur according to claim 1, wherein the contact surface of thepushing element is laterally spaced toward the outer laterally facingsurface from the inner laterally facing surface when the pushing elementis in the first position at rest in order to be activated by the chainmoving in the chain receiving slot.
 18. The bicycle front derailleuraccording to claim 1, wherein the inner laterally facing surface of theinner chain guide member has a forward most edge and a rearward most,and the entire contact surface is longitudinally disposed between theforward most edge and the rearward most edge of the inner laterallyfacing surface.
 19. The bicycle front derailleur according to claim 18,wherein the pushing element is longitudinally disposed closer to theforward most edge than the rearward most edge of the inner laterallyfacing surface.